FIG. 1 shows an OLED device 100. The OLED device comprises one or more organic functional layers 110 between first and second electrodes 105 and 115 on a substrate. The electrodes can be patterned to form, for example, a plurality of OLED cells to create a pixelated OLED device. Bond pads 150, which are coupled to the first and second electrodes, are provided to enable electrical connections to the OLED cells. A cap 160 is mounted on the substrate to encapsulate the device. The cap is mounted on a cap sealing frame 135, which typically has a width (WSP) of about 0.5-2 mm. Since the active and electrode materials of the OLED cells are sensitive and can be easily damaged from mechanical contact, the cap provides a cavity 145 to prevent the cap from physically contacting the OLED cells. The cavity also allows for the placement of desiccant materials to cope with finite leakage rate of the device. Leakage of oxygen and moisture into the device is a very critical issue since the device degrades rapidly when it is exposed to water or oxygen.
Conventional OLED devices have a thickness (TD) that exceeds the width of the cap sealing frame (e.g., 2-5 mm) However, the demand for thin, lightweight and flexible devices requires the use of thinner components, such as the cap and the substrate. Decreasing the thickness of the cap and substrate reduces the mechanical stability of the device, making it more prone to bending which can cause the cavity to collapse, thereby damaging the OLED cells.
As evidenced from the above discussion, it is desirable to provide a thinner OLED device without sacrificing device reliability.